/*
 * Copyright 2009-2011 Cedric Priscal
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>
#include "SerialPort.h"
#include "android/log.h"

static const char *TAG="serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)

static speed_t getBaudrate(jint baudrate)
{
	switch(baudrate) {
	case 0: return B0;
	case 50: return B50;
	case 75: return B75;
	case 110: return B110;
	case 134: return B134;
	case 150: return B150;
	case 200: return B200;
	case 300: return B300;
	case 600: return B600;
	case 1200: return B1200;
	case 1800: return B1800;
	case 2400: return B2400;
	case 4800: return B4800;
	case 9600: return B9600;
	case 19200: return B19200;
	case 38400: return B38400;
	case 57600: return B57600;
	case 115200: return B115200;
	case 230400: return B230400;
	case 460800: return B460800;
	case 500000: return B500000;
	case 576000: return B576000;
	case 921600: return B921600;
	case 1000000: return B1000000;
	case 1152000: return B1152000;
	case 1500000: return B1500000;
	case 2000000: return B2000000;
	case 2500000: return B2500000;
	case 3000000: return B3000000;
	case 3500000: return B3500000;
	case 4000000: return B4000000;
	default: return -1;
	}
}

static void throwException(JNIEnv *env, const char *name, const char *msg)
{
    jclass cls = (*env)->FindClass(env, name);
    /* if cls is NULL, an exception has already been thrown */
    if (cls != NULL) {
        (*env)->ThrowNew(env, cls, msg);
    }

    /* free the local ref */
    (*env)->DeleteLocalRef(env, cls);
}


/*
 * Class:     com_android_serialport_SerialPort
 * Method:    open
 * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
 */
JNIEXPORT jobject JNICALL Java_com_android_serialport_SerialPort_open(JNIEnv *env, jclass thiz, jstring path, jint baudrate, jint parity, jint dataBits, jint stopBit)
{
	int fd;
    int flags;
    speed_t speed;
    jobject mFileDescriptor;

    flags=0;
    /* Check arguments */
    {
        speed = getBaudrate(baudrate);
        if (speed == -1) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid baudrate");
            return NULL;
        }
        if (parity <0 || parity>2) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid parity");
            return NULL;
        }
        if (dataBits <5 || dataBits>8) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid dataBits");
            return NULL;
        }
        if (stopBit <1 || stopBit>2) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid stopBit");
            return NULL;
        }
    }

    /* Opening device */
    {
        jboolean iscopy;
        const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
        fd = open(path_utf, O_RDWR | flags);
        (*env)->ReleaseStringUTFChars(env, path, path_utf);
        if (fd == -1)
        {
            throwException(env, "java/io/IOException", "Cannot open port");
            return NULL;
        }
    }

    /* Configure device */
    {
        struct termios cfg;
        if (tcgetattr(fd, &cfg))
        {
            close(fd);
            throwException(env, "java/io/IOException", "tcgetattr() failed");
            return NULL;
        }
        cfmakeraw(&cfg);
        cfsetispeed(&cfg, speed);
        cfsetospeed(&cfg, speed);
        /* More attribute set */
        switch (parity) {
            case 0:
                    cfg.c_cflag &= ~PARENB; //清除校验位
                break;
            case 1:
                    cfg.c_cflag |= PARENB; //enable parity checking
                    cfg.c_cflag |= PARODD; //奇校验位
                    cfg.c_iflag |= (INPCK | ISTRIP);
                break;
            case 2:
                    cfg.c_cflag |= PARENB; //
                    cfg.c_cflag &= ~PARODD; //偶校验位
                    cfg.c_iflag |= (INPCK | ISTRIP);
                break;
            default:
                    cfg.c_cflag &= ~PARENB; //清除校验位
                break;
        }
        switch (dataBits) {
            case 5: cfg.c_cflag |= CS5; break;
            case 6: cfg.c_cflag |= CS6; break;
            case 7: cfg.c_cflag |= CS7; break;
            case 8: cfg.c_cflag |= CS8; break;
        }
        switch (stopBit) {
            case 1: cfg.c_cflag &= ~CSTOPB; break;
            case 2: cfg.c_cflag |= CSTOPB; break;
        }
        int rc = tcsetattr(fd, TCSANOW, &cfg);
        /*
        if (rc)
        {
            close(fd);
            throwException(env, "java/io/IOException", strcat("tcsetattr() failed: ", rc));
            return NULL;
        }
        */
    }

    /* Create a corresponding file descriptor */
    {
        jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
        jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
        jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
        mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
        (*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
    }

    return mFileDescriptor;
}


/*
 * Class:     com_android_serialport_SerialPort
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_com_android_serialport_SerialPort_close
  (JNIEnv *env, jobject thiz)
{
	jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
	jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

	jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
	jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

	jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
	jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

	LOGD("close(fd = %d)", descriptor);
	close(descriptor);
}

